This invention relates generally to door locks and more particularly to a mechanism providing rotary motion about one axis in response to rotary motion about another orthogonal axis while simplifying installation of the door lock.
Grip handle door locks generally are equipped with thumb latches which convert a linear motion of an operator's thumb into a rotary motion to withdraw a latchbolt and open a door. Most thumb actuated latches require field assembly of several components in the door preparation cavity. This assembly is difficult; because it involves holding the grip handle and other outside parts in place while bolts or screws are installed from the inside by the installer. It is awkward at best to hold parts in position with one hand on one side of a door while installing other parts and screws with the other hand from the other side. The result is excessive installation time and, sometimes, faulty performance of the lock mechanism.
A lot of the difficulty described is attributable to alignment of parts for a lever-rack-pinion-spindle combination. Even though no individual alignment is difficult, maintaining all the alignments simultaneously on one side of the door while installing fasteners from the other side is very difficult. Of course, not all thumb actuated latches are equally complex and difficult to install. Many are of simpler construction, but the two-sided alignment problem persists.
The foregoing illustrates limitations known to exist in present thumb actuated grip handle locks, and it would, therefore, be advantageous to provide an alternative directed to overcoming one or more of those limitations. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.